The document summarizes the physiological basis of hearing. It describes the functions of the external ear, middle ear, and inner ear. The middle ear increases pressure and attenuates sound waves through the ossicular lever action and attenuation reflex. The inner ear performs mechanical frequency analysis through the place principle and sensory transduction by converting sound waves to neural impulses through hair cells and neurotransmitters. Lesions in different parts of the auditory system cause different types and severities of deafness. Common tests to differentiate conductive and sensorineural deafness include Rinne's test and Weber's test.
